Note: Descriptions are shown in the official language in which they were submitted.
21~a~06
VACUUM VALVE CONTROL DEVICE AND VACUUM VALVE
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum valve control
device for a vacuum valve installed in a vacuum type sewage
collection system or a vacuum type chemicals transporting
apparatus, the valve body of which is driven by a pressure
difference between vacuum and atmosphere. More particularly,
the present invention relates to a vacuum valve control device
for controlling vacuum used for opening and closing the valve
bady.
to Usually, sewage discharged from every home flows to a
sewage disposal plant by the action of natural flow. However,
in this natural flow type sewage collection system, the
construction of sewer pipes is restricted by geography and the
condition of ground, and further the drain tends to be stopped
up. Forlthis reason, recently, attention has been given to a
vacuum type sewage collection system in which sewage discharged
from every home is forcibly transported by the action of
vacuum.
This vacuum type sewage collection system includes: a
2o vacuum valve unit in which sewage discharged from each hoihe is
stored when it flows by the action of natural flow; and a
vacuum station by which sewage is collected from the vacuum
valve unit through a vacuum pipe.
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2~.2~206
A vacuum valve unit is disclosed, for example, in U.S.
Patent 5,069,243. The vacuum valve unit disclosed in the above
patent includes: a suction pipe, one end of which is dipped in
sewage in the sewage tank; a vacuum valve, the pipe-shaped
communicating portion of which is connected with the other end
of the suction pipe; and a vacuum discharge pipe connected with
the communicating portion, wherein this vacuum discharge pipe
is connected with a vacuum pump disposed in a vacuum station
through a vacuum pipe. In the vacuum valve, the pipe-shaped
l0 communicating portion can be opened and closed when a valve
body disposed in the pipe-shaped communicating portion is
operated. The vacuum pipe is maintained to be in a vacuum
condition at a.l.l times by the action of the vacuum pump through
the vacuum pipe. When a predetermined amount of sewage is
stored in the sewage tank, the valve body of the vacuum valve
is opened by a pressure difference between the vacuum in the
vacuum discharge pipe and the atmosphere, so that the pipe-
shaped communicating portion can be opened. Due to the
foregoing, the vacuum discharge pipe in a vacuum condition is
. communicated with the suction pipe, so that sewage in 'the
sewage tank is sucked into the vacuum discharge pipe by the
action of vacuum, and transported to the vacuum station through
the vacuum pipe.
The valve body disposed in the communicating portion of the
vacuum valve usually closes the communicating portion. When
the valve operating chamber is put into a vacuum condition, the
21252~1~
valve body is pulled so that the communicating portion can be
opened . The vacuum condition in the valve operating chamber is
controlled by the vacuum valve control device.
This vacuum valve control device is connected with a liquid
level detecting pipe, the lower end of which is dipped in the
sewage in the sewage tank. When the liquid level of'sewage is
changed, the pressure in the liquid level detecting pipe is
changed, so that a liquid level detecting diaphragm provided in
the vacuum valve control device is resiliently deformed. Due
to to the deformation of the liquid detecting diaphragm, a
detecting valve fox introducing vacuum into the vacuum valve
control device is operated. Therefore, vacuum is activated on
a changeover valve disposed in the vacuum control valve. Due
to the foregoing, the changeover valve can be changed over, so
that the vacuum discharge pipe is communicated with the valve
operating chamber of the vacuum.valve. Accordingly, this valve
operating chamber is put in a vacuum condition. When the valve
operating chamber is put in a vacuum condition, the valve body
is pulled, and the communicating portion is opened.
2o As a result of the foregoing, the vacuum discharge pipe in
a vacuum condition is communicated with the suction pipe, so
that the inside of the suction pipe is also put in a vacuum
condition. Accordingly, sewage in the sewage tank is quickly
sucked into the suction pipe and vacuum discharge pipe. Then
the sewage is transported into a sewage collection tank in the
vacuum station through the vacuum pipe.
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212,~~~6
When sewage in the sewage tank is sucked in a moment, the
liquid level detecting diaphragm of the vacuum valve control
device gradually returns to the original condition . Due to the
foregoing, the operation of the detecting valve is released,
and the communication between the inside of the vacuum valve
control device and the vacuum discharge pipe is intercepted,
and at the same time the atmosphere is introduced into the
vacuum valve control device. Then the changeover valve is
changed over, so that the atmosphere is introduced into the
to valve operating chamber of 'the vacuum valve.
According to above mentioned U.S. Patent 5,069,243, a
damping mechanism is provided, by which the liquid level
detecting diaphragm is prevented from being resiliently
deformed in the case where sewage in the sewage tank is
discharged by the vacuum discharge pipe and the resilient
deformation of the liquid level detecting diaphragm is
21~52~~
the case where sewage is stored in the sewage tank. On the
other hand, in the case where the liquid level detecting
diaphragm is resiliently deformed after sewage in the sewage
tank has been discharged and the resilient deformation of the
' liquid level detecting diaphragm has been rs=leased, the damping
diaphragm is resiliently deformed, so that the communication
between the pressure adjusting chamber and the liquid level
detecting diaphragm is intercepted. As a result, the liquid
level detecting diaphragm is prevented from being resiliently
deformed. Therefore, there is no possibility that the
detecting valve is activated again, and there is no possibility
that the vacuum valve is opened.
In the vacuum sewage collecting apparatus described above,
sewage in the sewage tank is sucked and discharged in a moment.
1S Therefore, the liquid level of the sewage tank is suddenly
lowered. As a result, the liquid level of the liquid level
detecting pipe is also lowered so that the pressure in the
liquid level detecting pipe is also suddenly lowered. However,
as described above, since the damping diaphragm is provided
2o between the liquid level detecting pipe and the pressure
adjusting chamber, the pressure in the pressure adjusting
chamber is released only through a minute through-hole when the
pressure in the liquid detecting pipe is lowered. Therefore,
it takes time to cancel the resilient deformation of the liquid
25 level detecting diaphragm. As a result, even when sewage in
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2~.2~~~~
the sewage tank is discharged, an excessive amount of air is
sucked and the degree of vacuum is lowered.
Further, in the vacuum valve control device, the vacuum
force introduced into the pressure control chamber is released
to the atmosphere by a needle valve.
However, in the conventional vacuum type sewage collecting
system, as illustrated in Fig. 5, at a distant place from the
vacuum station 2 for collecting sewage into the sewage
collecting tank 1, the vacuum is lowered by the saw-tooth lift
4 provided in the vacuum pipe line 3. Therefore, in the case
of an opening time adjusting mechanism having a needle valve
provided in the controller of a conventional vacuum valve, the
needle valves are respectively adjusted at ad jacent and distant
places in such a manner that the opening time of a vacuum valve
located at a distant place is set longer so that an airlliquid
ratio in the pipe line can be maintained in a range (disclosed
in Japanese Unexamined Patent Publication (Kokai) Hei-2-
292427). In the case where the vacuum valves are
simultaneously opened, vacuum in the vacuum discharge pipe is
lowered. When this condition frequently occurs, a sufficient
amount of air is not supplied into the vacuum pipe line, so
that a water plug grows in the lift portion, and the 'entire
system is in trouble.
Furthermore, between an outer circumferential surface
provided in the housing of the vacuum valve and an inner
circumferential surface of the housing, a rolling diaphragm is
. ! ,, , , ,
2:~~52~~
disposed, by which the valve operating chamber in the housing
is airtightly isolated. This rolling diaphragm is made of
resilient rubber, and bent between the outer circumferential
surface of the plunger and the inner circumferential surface of
the housing so that the rolling diaphragm can be closely
brought into contact with the outer circumferential surface of
the plunger and the inner circumferential surface of the
housing. In the case where the plunger is slid by the action
of vacuum in the valve operating chamber in the housing, the
l0 rolling diaphragm is deformed so that the bent portion is moved
in a sliding direction of the plunger. As described above,
while a volume in the valve operating chamber is nat changed,
the plunger can be positively slid by the action of the rolling
diaphragm when vacuum is activated.
Usually, a portion close to the bent portion of the rolling
diaphragm is not closely . contacted with the inner
eircumferential surface of the housing, but the portion is
contacted with the rolling diaphragm which is closely contacted
with the outer circumferential surface of the plunger. When
one portion of the rolling diaphragm is contacted with another
portion with pressure as described above, there is a
possibility that the contacting portion is rubbed and worn away
in the case where the contacting portion is moved in accordance
with the sliding movement of the plunger. When the rolling
diaphragm is worn away, there is a possibility that
airtightness of the rolling diaphragm is deteriorated. When
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2125~~G
airtightness of the rolling diaphragm is deteriorated,
airtightness of the valve operating chamber can not be
maintained, and the plunger can not be driven even when the
valve operating chamber is put in a vacuum condition.
Therefore, in order to suppress the abrasion of the rolling
diaphragm, a method is put into practical use, in which a
surface of the rolling diaphragm is coated with lubricant such
as silicon grease or silicon oil. However, the coated
lubricant permeates into the rolling diaphragm made of
1o resilient material, so that the effect of the lubricant can not
be exerted over a long period of time. For this reason, the
rolling diaphragm must be replaced in a short period of time.
SUMMARY OF THE INVENTION
The present invention has been achieved to solve the above
problems. It is an object of the present invention to provide
a vacuum valve control device by which the vacuum valve can be
quickly closed even after sewage in the sewage tank has been
discharged by the action of vacuum.
It is another object of the present invention to operate a
2o vacuum valve at an appropriate opening time in accordance with
the vacuum in a vacuum discharge pipe so that an air/'liquid
ratio in the pipe line can be maintained in a predetermined
range, and a vacuum type liquid collecting/transporting
apparatus can be stably operated.
_ 8 _
It is a further object of the present invention to provide
a vacuum valve in which the rolling diaphragm for airtightly
separating the valve operating chamber can be stably used over
a long period of time.
In order to accomplish the above object, the present
invention is to provide a vacuum valve control device provided
in a vacuum valve which opens and closes with vacuum a pipe-
shaped connecting section for connecting a vacuum discharge
pipe in a vacuum condition with a suction pipe for sucking
liquid in a tank, said vacuum valve control device controlling
the opening and closing operations of said vacuum valve, said
vacuum valve control device comprising: liquid level detecting
pipe section, the inside pressure of which fluctuates in
accordance with the fluctuation of a liquid level in the tank;
a pressure adjusting chamber communicated with said liquid
level detecting pipe section; a liquid level detecting
diaphragm resiliently deformed when the pressure in said
pressure adjusting chamber is activated on said diaphragm
through a communicating hole; a changeover valve changed over
2o by the action of vacuum so that vacuum or atmosphere can be
selectively supplied to said vacuum valve; a detection valve
for controlling the supply and stop of vacuum to' said
changeover valve; a plunger for changing over said detection
valve being driven by the resilient deformation of said liquid
level detecting diaphragm; and a damping diaphragm disposed
between said liquid level detecting pipe section and said
_ 9 _
pressure adjusting chamber, said damping diaphragm having at
least one small through-hole so that said damping diaphragm is
not resiliently deformed when the pressure in said liquid level
detecting pipe section is gradually increased, said damping
diaphragm being resiliently deformed by the decompression of
the pressure adjusting chamber so that a communicating hole
formed between said pressure adjusting chamber and said liquid
level detecting diaphragm can be closed, said damping diaphragm
being capable of releasing the pressure from its peripheral
1o portion into the liquid level detecting pipe section when the
pressure in the pressure adjusting chamber is suddenly
increased,
The present invention is to provide a vacuum valve for
opening and closing a communicating section between a suction
pipe communicated with a tank, and awacuum discharge gipe
communicated with a vacuum source, the vacuum valve comprising o
a valve body for opening and closing the communicating section;
a valve operating chamber for accommodating a plunger connected
with the valve body; a closing force giving means for giving a
2o cloying force to the valve body accommodated in the valve
operating chamber; and a controller for giving an opening force
to the valve body by impressing a vacuuni upon the valve
operating chamber, wherein the controller includes a changeover
valve capable of changing over between a vacuum passage and an
atmospheric passage in the valve operating chamber, a liquid
level detecting diaphragm operated responding to a liquid level
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21~~2~~
in a tank, a pressure control chamber for giving a vacuum force
to the changeover valve so that the vacuum passage can be
connected with the valve operating chamber, a detecting valve
provided in the pressure control chamber, the detecting valve
being capable of introducing a vacuum force into the pressure
control chamber, a plunger directly driven by the liquid level
detecting diaphragm, the plunger being inserted into the
pressure control chamber so as to drive the detecting valve,
and an opening time adjusting valve to be opened so that a
to vacuum force introduced into the pressure control chamber can
be released, wherein the opening time is automatically
controlled by vacuum in the vacuum discharge pipe.
Furthermore, according to the present invention, the
rolling diaphragm is resilient so that it can be deformed in
is accordance with the movement of the 'plunger, in which the
rolling diaphragm contains a Lubricant so that the lubricant
can ooze out from the surface of the rolling diaphragm.
Furthermore, the rolling diaphragm includes a large diameter
section formed at one end capable of coming into pressure
2o contact with the inner surface of the valve operating chamber
in a free condition before assembly, a small diameter section
formed at the other end capable of coming into pressure contact
with the outer surface of the plunger, and a tapered section
formed in the middle between these large and small diameter
25 sections.
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In the vacuum valve control device of the present
invention, when the pressure in the liquid level detecting pipe
is increased in accordance with an increase of the liquid level
in the tank, the pressure in the pressure adjusting chamber is
increased without resilient deformation of the damping
diaphragm, so that the liquid level detecting diaphragm is
resiliently deformed. Due to the resilient deformation of the
liquid level detecting diaphragm, the plunger is driven, and
the detecting valve is operated, and the changeover valve is
to put in a vacuum condition. When the changeover valve is put in
a vacuum condition, the changeover valve is operated, and the
inside of the vacuum valve is put in a vacuum condition, so
that the vacuum valve is opened. As a result, the
communicating portion between the suction gipe in the tank and
the vacuum discharge pipe is opened, awd the suction pipe is
put in a vacuum condition, so that sewage in the tank is
discharged through the suction pipe and the vacuum discharge
pipe by the action of vacuum.
When the liquid level in the tank is lowered, pressure in
the liquid level detecting pipe is lowered, and pressure in the
pressure .adjusting chamber is quickly released through the
periphery of the damping diaphragm. Therefore, the resilient
deformation of the liquid level detection diaphragm is quickly
canceled. Due to the foregoing, the operation of the detecting
valve conducted by the plunger is stopped, and the changeover
valve is operated so that the atmosphere can be introduced into
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2~.2~~~6
the vacuum valve, and then the vacuum valve is closed by the
action of the introduced atmosphere.
When the liquid level detecting diaphragm is resiliently
deformed in the case where the resilient deformation of the
liquid level detecting diaphragm is canceled, the pressure
adjusting chamber is put in a decompressed condition, and the
damping diaphragm is resiliently defornned, so that the
communicating portion with the liquid level detecting diaphragm
is closed. Due to the foregoing, the liquid level detecting
1o diaphragm can be prevented from being resiliently deformed.
Accordingly, there is no possibility that the detecting valve
is operated again.
Furthermore, when a valve lift of the opening time
adjusting valve is automatically controlled in accordance with
the vacuum transmitted from the vacuum discharge pipe, (a) the
higher the vacuum is, the larger the valve lift of the opening
time adjusting valve is increased, so that the vacuum valve is
closed in a short period of time, and (b) the lower the vacuum
is, the smaller the valve lift of the opening time adjusting
2o valve is decreased, so that the vacuum valve is opened over a
long period of time. Due to the foregoing, an air/liquid ratio
in the pipe line can be maintained in a predetermined range,
and the vacuum type liquid collecting/transporting apparatus
can be stably operated.
Moreover, in the vacuum valve of the present invention, the
rolling diaphragm for separating the valve operating chamber in
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~1~~~~6
the housing to be maintained vacuum contains a lubricant, so
that the lubricant successively oozes out from the surface of
the rolling diaphragm. The lubricant that has oozed out from
the surface of the rolling diaphragm suppresses the abrasion of
the rolling diaphragm in the case where a portion of the
diaphragm close to the bent portion is rubbed when the plunger
moves in the valve operating chamber. Furthermore, under a
free condition before assembly, one end portion of the rolling
diaphragm is made to be a large diameter portion, the other end
1o portion is made to be a small diameter portion, and the middle
portion is made to be a tapered portion. Accordingly, when 'the
rolling diaphragm is used, the folded surfaces in the
intermediate bent portion of the rolling diaphragm are not
contacted with each other, so that abrasion is not caused by
rubbing.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a sectional view of the vacuum type sewage
collecting apparatus showing a using condition of the vacuum
valve having the vacuum valve control device of the present
invention;
Figs. ~A and 2B are longitudinal sectional view of the
212;~2,~~
Fig. 4 is an enlarged sectional view showing the primary
portion of the vacuum valve control device;
Fig. 5 is a view showing a model of the vacuum type sewage
collecting system;
Fig. 6A is a sectional view showing the controller section;
Fig. 6B is an enlarged sectional view showing the valve
portion of Fig. 6A;
Fig. 7A is another sectional showing the controller section
of the third embodiment;
1o Figs. 7B and 7C are views showing a model of the duckbill
valve;
Fig. 8A is another sectional view showing the controller
section of the third embodiment;
Figs. 8B and 8C are views shocoing a model of the flexible
conical orifice valve;
Fig. 9 is a view showing a.model of the exemplary opening
Image
212~2~~
discharge pipe 14 and that of the vacuum pipe are maintained in
a vacuum condition at all times by the vacuum pump disposed in
the vacuum station. Consequently, when the communicating
section 28 is opened, the vacuum discharge pipe 14 is
communicated with the suction pipe 13, so that sewage in the
sewage tank 11 is sucked into the suction pipe 13 and quickly
transported to the sewage collecting tank in the vacuum station
by the action of vacuum in the communicating section 28 and the
vacuum discharge pipe 14.
l.o A liquid level detecting pipe 37 is vertically provided in
the sewage tank 11, and a lower end of the liquid level
detecting pipe 37 is dipped in the sewage stored in the sewage
tank 11. This liquid level detecting pipe 37 is communicated
with the inside of a vacuum valve control device 27 provided in
the vacuum valve 15 through a flexible~hose 38. Therefore, a
change in pressure caused by .the fluctuation of the liquid
level in the sewage tank 11 can be transmitted to the vacuum
valve control device 27. The vacuum valve control device 27
controls the vacuum in a valve operating chamber 25 in the
2o vacuum valve 15 in accordance with a change in the liquid level
of sewage in the sewage tank 11 detected by the liquid level
detecting pipe 37.
The inside of the vacuum discharge pipe 14 is communicated
with the vacuum valve control device 27 through a flexible hose
41, so that the vacuum condition in the vacuum discharge pipe
14 is transmitted to the vacuum valve control device 27.
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Further, an atmosphere communicating pipe 43 is communicated
with the vacuum valve control device 27 through a flexible hose
44. An upper end of this atmosphere communicating pipe 43 is
open to the atmospheric pressure on the ground surface.
Accordingly, atmosphere introduced from the atmosphere
communicating pipe 43 is introduced to the inside of the vacuum
valve control device 27 through the flexible hose 44. This
atmosphere communicating pipe 43 is also communicated with the
valve operating chamber 25 of the vacuum valve 15 through a
1o flexible hose 46.
Figs . 2A and 2B are longitudinal sectional views of the
vacuum valve 15. This vacuum valve 15 includes; a first
cylindrical housing 21 integrated with the communicating
section 28 in which the valve body 24 is provided, wherein the
first cylindrical housing 21 is communicated with the inside of
the communicating section 28; and a second cylindrical housing
22 connected with 'the upper portion of the first housing 21
through a band cramp 23. In this case, the first housing 21 is
disposed forming an angle of 45° with respect to the
2o communicating section 28 which is horizontally disposed. The
inside of the first housing 21 is divided into an upger and a
lower portion by a bulkhead 21a, and the valve operating
chamber 25 is disposed on the upper side of this bulkhead 21a.
A valve rod 29 penetrates the center of the bulkhead 21a,
and a valve body 24 for opening and closing the communicating
section 28 is attached to the lower end of this valve rod 29.
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The upper end of the valve rod 29 is disposed in the valve
operating chamber 25, and attached to the bottom surface of a
cylindrical plunger 30, the upper surface of which is open.
This plunger 30 is slidably provided in the valve operating
chamber 25, and pushed by a pushing spring 26 provided in the
valve operating chamber 25 so that the valve body 24 can close _
the communicating section 28.
A resilient rolling diaphragm 31 is provided, between the
first and second housings 21, 22. This rolling diaphragm 31 is
to fixed under the condition that the periphery of the rolling
diaphragm 31 is placed between the first and second housings
21, 22. A portion close to the outer periphery of the rolling
diaphragm 31 closely comes into contact with the inner
circumferential surface of the second housing 22. Further, a
central side portion of the rolling diaphragm 31 close to the
inner side of a portion coming into contact with the inner
circumferential surface of the second housing 22 is bent by an
angle of 360°. A portion close to the inside of the bent
portion closely comes into contact with the side surface of the
2o plunger 30, and further a central portion on the inside of that
portion closely comes into contact with the bottom surface of
the plunger 30. The valve rod 29 penetrates the center of the
rolling diaphragm 31 covering the bottom surface of the plunger
30.
The vacuum valve control device 27 of the present invention
is disposed at an upper end of the second housing 2?.. This
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vacuum valve control device 27 is engaged and connected with
the upper end of the second housing 22 through a band cramp 36.
This vacuum valve control device 27 is operated as follows.
When an amount of sewage in the sewage tank 11 is increased and
the pressure in the liquid level detecting pipe 37 is raised,
the valve operating chamber 25 is put in a vacuum condition,
and the plunger 30 is pushed and the valve body is pulled
against a force of the spring 26 so 'that the valve body can
open the communicating section 28. When the valve body 24 is
1o pulled, the communicating section 28 is opened, and then the
vacuum discharge pipe 14 and the suction pipe 13 are put in a
communicating condition. Therefore, sewage in the sewage tank
11 is transported through the vacuum discharge pipe 14 by the
action of vacuum activated in the vacuum discharge pipe 14.
Fig . 3 is a longitudinal sectional view of the vacuum valve
control device 27. This vacuum valve control device 27
includes a casing composed of five cases, which are the first
case 51 to the fifth case 55. The first case 51 to the fifth
case 55 are sequentially disposed from the upside, and
2o integrated into one body with bolts. Usually, the fourth case
54 is engaged with an upper end of the second housing 22 of the
vacuum valve 15 and fastened by a band cramp 36 (shown in
Figs. 2A and 2B).
A liquid detecting pipe section 56 is mounted on an upper
surface of the uppermost first case 51, and a flexible hose 38
connected with the liquid level detecting pipe 37 is attached
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2~~52~6
to the liquid level detecting pipe section 56. An atmospheric
pressure connecting pipe section 58 is integrated with the
third case 53, and a flexible hose 44 connected with an
atmospheric communicating pipe 43 is connected with the
atmospheric pressure connecting pipe section 58. Consequently,
the pressure inside the atmospheric pressure connecting pipe
section 58 is the same as the atmospheric pressure. A vacuum
connecting pipe section 57 is integrated with the third case
53, and a flexible hose 41 communicated with the vacuum
1o discharge pipe 14 is connected with the vacuum connecting pipe
section 57. Consequently, the inside of the vacuum connecting
pipe section 57 is pit in a vacuum condition in the same manner
as the vacuum discharge pipe 14. Further, a communicating pipe
section 93 is integrated with the lowermost fifth case 55 in
such a manner that the communicating pipe section 93 protrudes
downward from the fifth case 55, and the communicating pipe
section 93 is communicated with the valve operating chamber 25
in the second housing 22.
An upper pressurizing chamber 81, which is open downward,
2o is provided on a lower surface of the uppermost first case 51.
An opening portion of this upper pressurizing chamber 81 is
airtightly covered with a liquid level detecting diaphragm 60
disposed between the first case 51 and the lower second case
52. A lower decompressing chamber 82, which is open upward, is
formed in an upper portion of the second case 52. An opening
of this lower decompressing chamber 82 is covered with the
- 21 -
liquid level detecting diaphragm 60. Consequently, the liquid
level detecting diaphragm 60 isolates the upper pressurizing
chamber 81 from the lower decompressing chamber 82.
The lower decompressing chamber 82 in the second case 52 is
covered with a lower surface section 52a, and a through-hole 94
is vertically formed in this lower surface section S2a. This
through-hole 94 is communicated with a communicating passage
53c which is communicated with the atmospheric pressure
connecting pipe section 58 provided in the third case 53,
1o wherein the communicating passage 53c makes a right angle with
the atmospheric pressure connecting pipe section 58.
Accordingly, the lower decompressing chamber 82 is communicated
with the atmospheric pressure connecting pipe section 58.
The third case 53 disposed under the second case 52 is
provided with a pressure control chamber 83 which is open
upward to the upper central portion. An upger decompressing
chamber 84 isolated by the bulkhead 53a is provided under this
pressure control chamber 83. This upper decompressing chamber
84 is open downward, and the opening is airtightly covered with
2o a valve driving diaphragm 70 disposed between the third and
fourth cases 53, 54. A lower decompressing chamber 85, which
is open upward, is provided at 'the center of the upper surface
of the fourth case 54. An opening of this lower decompressing
chamber 85 is airtightly covered with the valve driving
diaphragm 70. Consequently, the valve driving diaphragm 70
airtightly isolates the upper pressurizing chamber 84 from the
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2~.~~~~~
lower decompressing chamber 85. A suction chamber 86, which is
isolated from the lower pressurizing chamber 85 by the bulkhead
54a, is formed at a lower central portion of the fourth case
54. This suction chamber 86 is open downward, and its opening
is covered with the lowermost fifth case 55. This suction
chamber 86 is communicated with a communicating pipe section 93
communicated with the valve operating chamber 25 of the vacuum
valve 15.
A pressure adjusting chamber 102 open upward is provided on
to an upper side surface of the first case 51. Fig. 4 is an
enlarged sectional view of the pressure adjusting chamber 102.
An annular groove 111. is formed in the periphery of the opening
on the upper surface of the pressure adjusting chamber 102,
wherein an appropriate gag is formed between the annular groove
111 and the inner circumferential surface of the opening. An
annular support portion 112 protruding upward is provided
between the groove 111 and the inner circumferential surface of
the opening in such a manner that the annular support portion
2:~~52~6
provided. This flange 56a is mounted on the first case 51 in
such a manner that the flange 56a covers the opening on the
upper surface of the pressure adjusting chamber 102. A cutout
portion 56b surrounding the annular groove 111 is formed in the
flange 56a so that an appropriate gap can be formed between the
cutout portion 56b and the upper surface of the damping
diaphragm 59. Accordingly, the damping diaphragm 59 is opposed
to the inside of the cutout portion 56b, and its outer
periphery is not fixed but it is simply put on the support
1o portion 112.
A flexible hose 38 (shown in Figs. 2A and 2B) is connected
with the liquid level detecting pipe section 56, and the liquid
level detecting pipe 37 dipped in sewage in the sewage tank is
communicated with the flexible hose 38.
A valve seat 101 opposed to the end opening of the liquid
level detecting pipe section 56 is provided in the pressure
adjusting chamber 102 in such a manner 'that the valve seat 101
is protruded so that it can approach the liquid level detecting
pipe section 56. A communicating hole 103 for communicating
2o the pressure adjusting chamber 102 with the upper pressurizing
chamber 81, is vertically provided on the valve seat 101. The
inner diameter of this communicating' hole 103 is constant.
One through-hole 59a, the diameter of which is minute, is
formed on the damping diaphragm 59 so that the damping
diaphragm 59 can not be deformed when the pressure in the
liquid detecting pipe section 56 is gently increased. This
- 24 -
through-hole 59a is formed at a position located outside of the
end surface opening of the communicating hole 103. The
diameter of this through-hole 59a is sufficiently smaller than
that of the opening of the liquid level detecting pipe section
56, further the diameter of the through-hole 59a is smaller
than that of the communicating hole 103 of the valve seat 101.
Preferably, a diameter of the through-hole 59a is determined in
such a manner that area of the through-hole is less than 1!8 of
the cross-section of the communicating hole 103, that is, the
to diameter of the through-hole 59a is not more than 0.4 [mm], and
preferably the diameter of the through-hole 59a is about 0.3
[mm]. In the case where the pressure in the liquid level
detecting pipe ser_tion 56 is increased by a gradual increase of
the level of sewage flowing into the sewage tank 11, the
aforementioned damping diaphragm S9 is mot resiliently deformed
since the pressure is released to the pressure adjusting
chamber 102 through the minute 'through-hole 59a.
Qn the other hand, when the pressure in the pressure
adjusting chamber 102 is reduced, the damping diaphragm 59
2o comes into contact with the upper surface of the valve seat 101
as illustrated by a two-dotted chain line in Fig. 4, so that
the communicating hole 103 in the valve seat 101 is airtightly
closed by a portion of the damping diaphragm 59 where the
though-hole 59a is not formed.
In the case where the pressure in the pressure adjusting
chamber 102 is increased, a gap is formed between the suppart
2125206
portion 112 and the outer periphery of the damping diaphragm 59
placed on the support portion 112. Therefore, the pressure in
the pressure adjusting chamber 102 is released through the gap.
A push button 64 for manually operating the vacuum valve
control device 27 is provided in the center of the upper
surface of the first case 51. This push button 64 is provided
with a plunger 61 which penetrates a through-hole 51b formed in
the center of the upper surface of the first case 51. This
plunger 61 is slidably supported in the through-hole 51b. This
1o plunger 61 is pushed upward by a pushing spring 63, and covered
with a resilient cover 62. When this push button 64 is
pressed, the plunger 61 is lowered resisting the pushing force
of the push spring 63, so that the center at the liquid level
detecting diaphragm 60 is pushed downward, and the liquid level
detecting diaphragm 60 is resiliently deformed.
The liquid level detecting diaphragm 60 is disposed between
the upper pressurizing chamber 81 in the first case 51 and the
lower decompressing chamber 82 in the second case 52, and at
the center of the liquid level detecting diaphragm 60, a
2o plunger 65 is provided, which vertically penetrates the lower
decompressing chamber 82. This plunger 65 penetrates the
center of the lower surface 52a of the second case 52 disposed
at a lower position of the lower decompressing chamber 82.
Then the plunger 65 enters the pressure control chamber 83
formed in the third case 53. A push spring 66 is engaged with
the plunger 65 in a region between the lower surface 52a and
- 26 -
. . ~12~206
the liquid level detecting diaphragm 60. By the push spring
66, the plunger 65 and the liquid level detecting diaphragm 60
are pushed upward. An 0-ring 67 engaging with the plunger 65
that has entered the pressure adjusting chamber 83, is attached
onto a lower surface of the lower surface portion 52a. By the
action of this 0-ring, a boundary between the plunger 65 and
the pressure control chamber 83 is sealed.
A communicating passage 57a for communicating the pressure
control chamber 83 with the vacuum connecting pipe section 57
1o is provided in the third case 53 in which the pressure control
chamber 83 is provided. A vertical communicating passage 53b,
the upper. end of which is communicated with the vacuum
connecting pipe section 57, is provided in the third case 53.
Further, this communicating passage 53b is communicated with
the communicating passage 54b vertically penetrating the fourth
case 54. This communicating passage 54b is communicated with
a suction passage 87 horizontally provided in the lowermost
fifth case 55.
An opening portion of the communicating passage 57a
2o communicated with the vacuum connecting pipe section 57 in the
third case S3, is formed in the pressure control chamber 83.
This opening portion is opened and closed by the detecting
valve 68 disposed in the pressure control chamber 83. In this
embodiment, a snap-action-valve is used for the detecting valve
68. The snap-action-valve includes: a leaf spring coming into
contact with the plunger 65 when the plunger 65 is lowered; and
- 27
212J~~D6
a tongue piece attached to an end of the leaf spring so that
the tongue piece can close an opening of the communicating
passage 57a by the pushing force of this lea:E spring. When the
plunger 65 is lowered and contacted with the leaf spring, the
tongue piece is moved upward so that the opening of the
communicating passage 57a can be opened. Due to the foregoing,
the pressure control chamber 83 is communicated with the vacuum
connecting pipe section 57 through the communicating passage
57a.
1o In the third case 53 in ~ohich the pressure control chamber
83 is provided, a communicating passage is formed, which
communicates the pressure control chamber 83 with the lower
decompressing chamber 82 in the second case 52 above the
pressure control chamber 83, and a needle valve 74 is disposed
in this passage. This needle valve 74 adjusts an amount of air
flowing into the pressure control chamber 83 when the
atmosphere is introduced into the lower decompressing chamber
82. Consequently, a period of time in which the atmosphere is
introduced into the pressure control chamber 83 is adjusted by
2o the needle valve 74.
The pressure control chamber 83 is isolated from the upper
decompressing chamber 84 disposed below the pressure cdntrol
chamber 83, by the bulkhead 53a of the third case 53. At the
center of the bulkhead 53a, a communicating hole 88 is
vertically formed, which communicates the pressure control
chamber 83 with the upper decompressing chamber 84. In the
_ 28 _
21~~2~~
upper decompressing chamber 84, a push spring 69 is provided,
which presses downward the valve driving diaphragm 70 for
separating the upper decompressing chamber 84 from the lower
pressurizing chamber 85 disposed below the upper decompressing
chamber 84. A rod-shaped changeover valve 71 vertically
penetrating the lower pressurizing chamber 85 is attached at
the center of the lower surface of the valve driving diaphragm
70.
A bulkhead 54a isolates the lower pressurizing chamber 85
1o from the suction chamber 86 which are respectively provided in
the fourth case 54, and the changeover valve 71 penetrates a
through-hole formed in this bulkhead 54a in the fourth case 54,
wherein a gap is formed between the changeover valve 71 and the
through-hole formed in this bulkhead 54a. A valve body 71a is
attached to a lower end of the changeover valve 71 which is
disposed in the suction chamber 86. A valve seat 72 is
provided in the through-hole of the bulkhead 54a through which
the changeover valve 71 is penetrated, and the valve body 71a
engages with the valve seat 72 so as to close the through-hole
when the valve body 71a is move upward. In the bulkhead 55a
disposed in a lower portion of the suction chamber 86 in 'the
fifth case 55, a through-hole is formed, which' communicates the
suction chamber 86 with the suction passage 87 horizontally.
provided below the suction chamber 86. In this through-hole,
a valve seat 73 is provided, with which the valve body 71a is
- 29 -
2~25~~~
engaged so as to close the through-hole when the valve body 71a
is lowered.
In the fourth case 54 in which the lower pressurizing
chamber 85 is provided, a communicating passage 54c, one end of
which is communicated with the lower pressurizing chamber $5,
is formed. The other end of this communicating passage 54c is
communicated with the lower end of a communicating passage 92
vertically provided in the third case 53 disposed above the
fourth case 54. The upper end of this communicating passage 92
1o is communicated with the atmospheric pressure connecting pipe
section 58. Accordingly, when the atmosphere is introduced to
the atmospheric pressure connecting pipe section 58, the
atmosphere is introduced into the lower pressurizing chamber 85
through the communicating passages 92 and 54c.
The vacuum valve 15 having the construction described above
is operated as follows. The vacuum connecting pipe section 57
in the vacuum valve control device 27 is communicated with the
vacuum discharge pipe 14. Therefore, the inside of the vacuum
connecting pipe section 57 is maintained in a vacuum condition.
2o When an amount of sewage in the sewage tank 11 is gradually
increased and the pressure in the liquid level detecting pipe
37, the lower end of which is dipped in the sewage, is
gradually increased under the aforementioned condition, the
pressure in the liquid level detecting pipe section 56 of the
z5 vacuum valve control device 27 cor~ununicated with the liquid
level detecting pipe 37 through the flexible hose 38, is
- 30 -
~12~2~~
gradually increased. Due to the .foregoing, the pressure in the
pressure adjusting chamber 102 is gradually increased through
the minute through-hole 59a formed on the damping diaphragm 59
covering the opening of the liquid level detecting pipe section
56. At this time, the damping diaphragm 59 is not resiliently
deformed, so that the communicating hole 103 of the valve seat
101 is not closed. Accordingly, when the pressure in the
pressure adjusting chamber 102 is gradually increased., the
pressure in the upper pressurizing chamber 81 is gradually
to increased which communicates with the pressure ad7ustina
chamber 102 through the communicating hole 103 of the valve
seat 101.
When the pressure in the upper pressurizing chamber 81 is
gradually increased, the liquid level detecting diaphragm 60 is
gradually deformed downward in the manner of resilience. The
lower decompressing chamber 82.disposed below the liquid level
detecting diaphragm 60 is communicated with the atmospheric
pressure connecting pipe section 58 through the through-hole 94
and the communicating passage 53c. Further this atmospheric
pressure connecting pipe section 58 is communicated with the
atmosphere communicating pipe 43 through the flexible hose 44.
Therefore, when the liquid level detecting diaphragm 60 is
gradually deformed downward in the manner of resilience, air in
the lower decompressing chamber 82 is discharged. Due to the
foregoing, the plunger 65 attached to the liquid level
detecting diaphragm 60 is moved downward.
_ 31 _
~12~20~
When the plunger 65 is moved downward, 'the detecting valve
68 provided in the pressure control chamber 83 is pushed by the
plunger 65, so that an opening of the communicating passage 5?a
located in the pressure control chamber 83 is opened. Due to
the foregoing, the pressure control chamber 83 is put in a
vacuum condition through the communicating passage 57a which
has been put in a vacuum condition. When the pressure control
chamber 83 is put in a~ vacuum condition, the upper
decompressing chamber 84 disposed below the bulkhead 53a is
to also put in a vacuum condition through the communicating hole
88 formed in the bulkhead 53a. The lower pressurizing chamber
85 disposed below the upper decompressing chamber. 84 through
the valve driving diaphragm 70 is communicated with the
atmospheric pressure connecting pipe section 58 through the
communicating passages 54c and 92,~ so that the lower
pressurizing chamber 85 is open to the atmosphere.
Accordingly, the valve driving diaphragm 70 is resiliently
deformed upward resisting the push spring 69 when the pressure
in the upper decompressing chamber 84 is reduced.
2o When the valve driving diaphragm 70 is resiliently deformed
upward, the changeover valve 71 attached to this valve driving
diaphragm 70 is moved upward, so that the valve body 71a
attached to a lower end of the changeover valve 71 opens the
valve seat 73 provided in a lower portion of the suction
chamber 86, and at the same time the valve body 71a closes the
valve seat 72 provided in an upper portion of the suction
_ 32 _
2~.2 ~~~~
chamber 86. Under the condition described above, the suction
chamber 86 is communicated with the suction passage 87 through
the lower valve seat 73, and the suction chamber 86 is put in
a vacuum condition being affected by the vacuum condition in
the suction passage 87 communicated with the vacuum connecting
pipe section 57 through the communicating passages 54b and 53b.
The communicating pipe section 93 communicated with this
suction chamber 86 is also put in a vacuum condition. Due to
the foregoing, the valve operating chamber 25 of the vacuum
1o valve 15 communicated with the communicating pipe section 93 is
put in a vacuum condition.
When the valve operating chamber 25 in the vacuum valve 15
is put in a vacuum condition, the plunger 30 is pulled up
resisting the pushing force of the push spring 26. Therefore,
the valve body 24 connected with this 'plunger 30 through the
valve rod 29 is moved upward. .As a result, the communicating
section 28 is put in an open condition, and the vacuum
discharge pipe 14 and the suction pipe 13 are communicated with
each other through the ccimmunicating section 28, and sewage in
2o the sewage tank 11 is sucked into the suction pipe 13 by the
action of vacuum in the vacuum discharge pipe 14. Sewage in
the sewage tank 11 is sucked into the suction pipe 13' in a
moment, and further sucked into the vacuum discharge pipe 14
through the communicating section 28. After that, sewage is
collected to the sewage collection tank through the vacuum pipe
which has been put in a vacuum condition.
- 33 -
~~;;'~~~
When sewage in the sewage tank 11 is discharged in a
moment, pressure in the liquid level detecting pipe 3? is
quickly lowered, and pressure in 'the liquid level detecting
pipe section 56 is also quickly lowered. Due to the foregoing,
the damping diaphragm 59 in the pressure adjusting chamber 102
is sucked into the liquid level detectinc3 pipe section 56.
Since the outex periphery of the damping diaphragm 59 is not
filed to the support portion 112 disposed around the pressure
adjusting chamber 102 but the outer periphery of the damping
1o diaphragm 59 is placed and supported by the support portion
112, a gap is formed between this support portion 112 and the
damping diaphragm 59, and pressure in the pressure adjusting
chamber 102 is quickly released to the liquid level detecting
pipe section 56.
Since the pressure adjusting chamber 102 is communicated
with the upper pressurizing chamber 81 through the
communicating hole 103, air in the upper pressurizing chamber
81 is also quickly discharged into the liquid level detecting
pipe section 56 through the pressure adjusting chamber 102.
2o Due to the forging, the liquid level detecting diaphragm 60
that has been resiliently deformed downward is returned to its
initial condition.
Since the lower decompressing chamber 82 disposed below the
liquid level detecting diaphragm 60 is open to the atmosphere
through the long atmosphere communicating pipe 43, the
atmosphere does not flow into the lower decompressing chamber
- 34 -
2~.~~~~~
82 through the atmosphere communicating pipe 43. However, air
in the upper pressurizing chamber 81 disposed above the liquid
level detecting diaphragm 59 quickly flows out to the liquid
level detecting pipe section 56 through the damping diaphragm
60 when the pressure in the liquid level detecting pipe section
56 is quickly reduced. Therefore, the liquid level detecting
diaphragm 60 that has been resiliently deformed is quickly and
smoothly returned to its initial condition.
After the resilient deformation of the liquid level
to detecting diaphragm 60 has been quickly canceled by the action
of air flowing out from the periphery of the damping diaphragm
59, the plunger. 65 attached to the lower surface of the liquid
level detecting diaphragm 60 is moved upward. Then the
detecting valve 68 pushed by the plunger 65 returns to its
initial condition, and the detecting' valve 68 closes the
communicating passage 57a communicated with the vacuum
connecting pipe section 57. Due to the foregoing, the
communicating condition between the pressure control chamber 83
and the vacuum connecting pipe section 57 in a vacuum condition
2o is shut off.
At this time, the pressure control chamber 83 is in a
vacuum condition, however, this vacuum condition c'an be
canceled after a small time lag when the atmosphere flowing
into the lower decompressing chamber 82 from the atmosphere
connecting pipe section 58 through the communicating passage
r ,..at! '' , ..
. ....5:'. ,;, tr, i,,.
.: . , . ,;r
2~.252~16
53c and through-hole 94, gradually flows into the pressure
control chamber 83 through the needle valve ?4.
When the vacuum condition of the pressure control chamber
83 is canceled, the vacuum condition of the upper decompressing
chamber 84 communicated with the pressure control chamber 83
through the communicating hole 88 is also canceled, and the
valve driving diaphragm 70 is pushed downward by the push
spring 69, so that the upward resilient deformation of the
valve driving diaphragm 70 is canceled. Due to the foregoing,
1o the changeover valve 71 attached to the valve driving diaphragm
70 is moved downward, and the valve body 71a attached to the
lower end opens the valve seat 72 on the upper side, and at the
same time, closes the valve seat 73 on the lawer side. As a
result, the communicating pipe section 93 communicated with the
valve operating chamber 25 of the vacuum valve 15 is
communicated with the atmosphere connecting pipe section 58
through the suction chamber 86, the lower pressurizing chamber
85 disposed above the suction chamber, and the communicating
passages 54a and 92. Therefore, the atmosphere in the
2o atmosphere connecting pipe section 58 is introduced into the
communicating pipe section 93. Due to the foregoing, the
vacuum condition in the valve operating chamber 25 of the
vacuum valve 15 is canceled, and the plunger 30 of the vacuum
valve 15 is moved downward by the pushing force of the push
spring 26, so that the valve body 24 closes 'the communicating
section 28.
2~2~~~~
'Phe vacuum condition of the communicating pipe section 93
communicated with the valve operating chamber 25 is canceled by
the atmosphere introduced into the lower pressurizing chamber
85 from the atmosphere connecting pipe section 58 through the
communicating passage 92. The atmosphere connecting pipe
section 58 is also connected with the lower decompressing
section 82 through the communicating passage 53c extending
upward and the through-hole 94. A volume of the valve
aperating chamber 25 of the vacuum valve 15 is large, so 'that
1o a large amount of atmosphere flows into the valve operating
chamber 25 through the communicating pipe section 93.
Accordingly, there is a possibility that the pressure of the
lower decompressing chamber 82 is reduced, which is
communicated with the atmosphere connecting pipe section 58
through the communicating passage 53c and the through-hole 94.
In the case where the pressure in the lower decompressing
chamber 82 is reduced, the liquid level detecting diaphragm 60
is sucked downward and deformed a little, so that the pressure
in the upper pressurizing chamber 81 is also reduced. Due to
2o the foregoing, the pressure adjusting chamber 102 communicated
through the communicating hole 103 is decompressed. The minute
through-hole 59a is formed on the damping diaphragm S9 covering
the pressure adjusting chamber 102, however, the diameter of
the minute through-hole 59a is sufficiently smaller than that
of the communicating hole 103 formed in the valve seat 101.
Accordingly, the damping diaphragm 59 is resiliently deformed
37
21~':~
downward by the action of decompression in the pressure
adjusting chamber 102. Due to the foregoing, a portion of the
damping diaphragm 59 where the through-hole 59a is not formed,
closely comes into contact with an upper surface of the valve
seat 101, so that an opening on the upper surface of the
communicating hole 103 is closed. As a :result, air in the
pressure adjusting chamber 102 does not flow into the upper
pressurizing chamber 81 through the communicating hole 103.
Therefore, the liquid level detecting diaphragm 60 can be
to prevented from being resiliently deformed downward. Due to the
foregoing, the plunger 6S can be prevented from moving downward
and coming into contact with the detecting valve 68.
Therefore, the valve body 24 of the vacuum valve 15 can be
prevented from re-opening the communicating section 28.
Second Embodiment
In the vacuum valve control.device of the first embodiment,
the needle valve adjusts the amount of air by adjusting the gap
between the outer cylinder and the needle. The gap of the
needle valve that can provide an optimal opening time of the
2o vacuum valve is extremely small. Therefore, if the vacuum
valve is repeatedly operated for a long period of time, dust,
moisture and the like a.re introduced from outside, gradually
narrowing the small gap. As a result, the gap is varied so as
to increase the opening time, leaving the vacuum valve open in
the worst case.
- 38 -
According to the second embodiment, a cylindrical elastic
body is used as the opening time adjusting valve instead of a
conventional gap adjusting needle valve, so that the sectional
area of the air hole that can provide a relatively large air
s passage can be made variable by compression. The other
elements are similar to those of the first embodiment.
Therefore, even with a repeated operation of the vacuum valve
over a long period of time, dust, moisture and the like can
pass through the valve, so that the initially set opening time
of the vacuum valve can be maintained stably over a long period
of time.
An air release valve 74, which is an opening time ad justing
valve, is provided on the upper chamber 83 of the third case
53. The air release valve 74 is designed so that the
atmosphere is gradually introduced via an air hole 74A thereof
(Fig. 9). The air release valve 74 is formed of a thick,
cylindrical elastic body such as rubber or thermoplastic
elastomer. The inner diameter portion of the air release valve
74 constitutes the air hole 74A. An opening portion 74B of the
2o air hole 74A is formed on an end of the thick-walled portion.
The sectional area of the air hole 74A can be varied by
adjusting the degree of~compression axially applied to the ai'r
hole 74A by an opening time adjusting screw 102. The air
release valve 74 is used in the following way. When the vacuum
of the vacuum discharge pipe 14 is high, the opening time
adjusting screw 102 is loosened to increase the sectional area
- 39 -
21~J~~~6
of the air hole 74A of the air release valve 74 so that the
opening time of the vacuum valve can be decreased, and when the
vacuum of the vacuum discharge pipe 14 is low, the opening time
adjusting screw 102 is tightened to decrease the sectional area
of the air hole 74A of the air release valve 74 so that the
opening time of the vacuum valve can be increased.
Third Embodiment
A third embodiment of the present invention will be
explained as follows.
1o According to the third embodiment, an opening time
adjusting valve which is automatically controlled is provided.
The other eloments are similar to those of the first
embodiment.
(Example 1)
As shown in Figs. 6A and 6B, a diaphragm 102 is attached to
the needle valve 74, which is. balanced between the pushing
force of the spring 103 and the vacuum in the vacuum discharge
pipe 14 communicated with a~ passage 95, so that 'the needle
valve 74 is displaced to an appropriate position. When the
2o degree of vacuum in the vacuum discharge pipe 14 is high, the
valve lift of the needle valve 74 is increased, and when the
degree of vacuum is low, the lift of the needle valve 7'4 is
decreased.
According to this first example, the following mode of
operation can be provided. When the valve lift of the needle
valve 74, which is used as an opening time adjusting valve, is
- 40 -
212~?~~~
automatically controlled in accordance with the vacuum
transmitted from the vacuum discharge pipe 14, (a) the higher
the vacuum is, the larger the valve lift of the needle valve 74
is increased, so that the vacuum valve 1S is closed in a short
period of time, and (b) the lower the vacuum is, the smaller
the valve lift of the needle valve 74 is decreased, so that the
vacuum valve is opened over a long period of time. Due to the
foregoing, an air/liquid ratio in the pipe line can be
maintained in a predetermined range, and the vacuum 'type liquid
to collecting/transporting apparatus can be stably operated.
(Example 2)
The second example is distinguished from the first example
in that a needle valve 110 and a duckbill valve 120 are used as
opening time adjusting valves provided in the controller
section 27 as shown in Figs. 7A-7C. The other elements are
similar to those of the first example.
The needle valve 110 and the duckbill valve 120 are
provided in the passage 193 communicated with the inside and
outside of the upper chamber 83 (pressure control chamber) of y
a third case S3. In this embodiment, the duckbill valve 120 is
provided in the passage 193 farther than the needle valve 110.
The duckbill valve 120 may, however, be provided in the passage
193 closer to the upper chamber 83 than the needle valve 110.
The needle valve 110 is adjusted so as to spirally move
back and forth with respect to the valve seat provided within
- 41 -
2~.2~~'~~
the passage 193. The needle valve 110 is used by appropriately
adjusting the gap with respect to the valve seat. ,
The duckbill valve 120 can ad just the valve lift with a
vacuum force in the upper chamber 83 being applied to the outer
surface of a bill 121 thereof. When the vacuum force is high,
the valve lift of the duckbill valve 120 is increased due to a
large pressure difference between the atmospheric pressure
exerted upon the inner surface of the bill 121 and the high
negative pressure exerted upon the outer surface of the bill
121, and when the vacuum force is low, the valve lift of the
duckbill valve 120 is decreased due to a small pressure
difference between the atmospheric pressure exerted upon the
inner surface of the bill 121 and the low negative pressure
exerted upon the outer surface of the bill 121.
According to the second example, when the valve lift of the
duckbill valve 120, which is used as an opening time adjusting
valve, is automatically controlled in accordance with the
vacuum force in the chamber 83, in other words, the vacuum
transmitted from the vacuum discharge pipe 14, (a) the higher
2o the vacuum is, the larger the valve lift of the duckbill valve
120 is increased, so that the vacuum valve 15 is closed in a
short period of time, and (b) the lower the vacuum is,' the
smaller the valve lift of the duckbill valve 120 is decreased,
so that the vacuum valve is opened over a long period of time.
Due to the foregoing, an air/liquid ratio in the pipe line can
- 42 -
be maintained in a predetermined range, and the vacuum type
liquid collecting apparatus can be stably operated.
(Example 3)
The third example is distinguished from the first example
in that both a needle valve 110 and a flexible conical orifice
valve 130 are used as opening time adjusting valves provided in
the controller section 27 as shown in Figs. 8A-8C. The other
elements are similar to those of the first example.
The needle valve 110 and the orifice valve 130 are provided
1o in the passage 193 communicated with the inside and outside of
the upper chamber 83 (pressure control chamber) of the 'third
ease 53. Tn 'this embodiment, the orifice valve 130 is provided
at an opening of the passage I93 to the chamber 83. The
orifice valve 130 may, however, be provided in the passage 193
farther from the chamber 83 than the needle valve 110.
Similarly to the second embodiment, the needle valve 110 is
adjusted so as to spirally move back and forth with respect to
the valve seat provided in the passage 193. The needle valve
110 is used by appropriately adjusting the gap with respect to
2o the valve seat.
The orifice valve 130 is formed of a flexible elastic body
such as rubber and elastomer, and is designed so that the'valve
lift can be adjusted with a vacuum force in the chamber 83
applied to the outer surface of the cone. When the vacuum
force is high, the valve lift of the orifice valve 130 is
resiliently increased due to a large pressure difference
-
~~.~5206
between the atmospheric pressure exerted upon the inner surface
of the cone and the high negative pressure exerted upon the
outer surface of the cone, and when the vacuum force is low,
the valve lift of the orifice valve 130 is resiliently
decreased due to a small pressure difference between the
atmospheric pressure exerted upon the inner surface of the cone
and the low negative pressure exerted upon the outer surface of
the cone.
According to third example, when the valve lift of the
orifice valve 130, which is used as an opening time adjusting
valve, is automatically controlled in accordance with the
21~~~~~
rolling diaphragm is made of resilient rubber, and bent between
the outer circumferential surface of the plunger and the inner
circumferential surface of the housing so that the rolling
diaphragm can be closely brought into contact with the outer .
circumferential surface of the plunger and the inner
circumferential surface of the housing. In the case where the
plunger is slid by the action of vacuum in the valve operating
chamber in the housing, the rolling diaphragm is deformed so
that the bent portion is moved in a sliding direction of the
l0 plunger. As described above, while a volume in the valve
operating chamber is not changed, the plunger can be positively
slid by the action of the rolling diaphragm when vacuum is
activated.
Usually, a por-lion close to the bent portion of the rolling
diaphragm is not closely contacted with the inner
circumferential surface of the housing, but the portion is
contacted with the rolling diaphragm which is closely contacted
with the outer circumferential surface of the plunger. When
one portion of the rolling diaphragm is contacted with another
2o portion with pressure as described above, there is a
possibility that the contacting portion is rubbed and worn away
in the case where the contacting portion is moved in accordance
with the sliding movement of the plunger. When the rolling
diaphragm is worn away, there is a possibility that
airtightness of the rolling diaphragm is deteriorated. When
airtightness of the rolling diaphragm is deteriorated,
- 45 -
2~.~52~~6
airtightness of the valve operating chamber can not be
maintained, and the plunger can not be driven even when the
valve operating chamber is put in a vacuum condition.
Therefore, in order to suppress the abrasion of the rolling
diaphragm, a method is put into practical use, in which a
surface of the rolling diaphragm is coated with lubricant such
as silicon grease or silicon oil. However, the coated
lubricant permeates into the rolling diaphragm made of
resilient material, so that the effect of the lubricant can not
1o be exerted over a long period of time. For this reason, the
rolling diaphragm must be replaced in a short period of time.
The plunger disposed in the housing is connected w:Lth a
valve rod. This valve rod is inserted into a through-hole
formed in the housing. A valve body is attached to an end of
the valve rod located outside of the pausing. A shaft seal
comes into pressure contact with the valve rod so that the
valve rod can slide in an airtight condition with respect to
the through-hole. This shaft seal is also made of resilient
substance such as rubber. Therefore, when the shaft seal
2o slides along the valve rod, it is worn away, and airtightness
is deteriorated with the lapse of time.
For this reason, a surface of the shaft seal is coated with
lubricant in the same manner as that of the rolling diaphragm.
However, the coated lubricant permeates into the shaft seal
made of resilient material. Accordingly, there is a
possibility that the shaft seal. does not function in a short
46
212~2~~
period of time. Since the shaft seal comes into contact with
sewage flowing in the communicating section, lubricant coated
on the surface of the shaft seal is removed by sewage.
Consequently, there is a possibility that the effect of
lubricant on the shaft seal is exerted only in a shorter period
of time than that of the rolling diaphragm.
According to the fourth embodiment of the invention, the
rolling diaphragm 31 airtightly isolates the valve operating
chamber 25 in the first housing 21 and the second housings 22.
1o When the valve operating chamber 25 located above the rolling
diaphragm 31 is put in a vacuum condition, the plunger 30 is
moved upward by the action of vacuum. At this time, in
accordance with the movement of the plunger 30, the rolling
diaphragm 31 is successively peeled off from the outer
circumferential surface of the plunger 30 with which the
rolling diaphragm 31 has come .into contact, and at the same '
time the rolling diaphragm 31 successively comes into contact
with the inner circumferential surface of the second housing
22.
2o This rolling diaphragm 31 is made of rubber into which
lubricant such as silicon oil, silicon grease and DOP
(dioctylphthalate) is kneaded in the process of forming.
Therefore, the lubricant kneaded into rubber gradually oozes
out from the surface. Accordingly, from the surface of the
rolling diaphragm 31, lubricant oozes out at all times.
~~
21~~i2~6
Furthermore, a shaft seal 32 air tightly coming into
pressure contact with the outer circumferential surface of the
valve rod 29 is provided around the through-hole of the
bulkhead 21a through which the valve rod 29 is penetrated. In
the same manner as that of the shaft seal 32 described before,
this shaft seal 32 is made of rubber into which lubricant such
as silicon oil, silicon grease and DOP (dioctylphthalate) is
kneaded in the process of forming. Therefore, the lubricant
kneaded into rubber gradually oozes out from the surface.
to Accordingly, from the surface of the shaft seal 32, lubricant
oozes out at all times. The other elements are similar to
those of the first embodiment.
Due to the foregoing, the valve operating chamber 25 above
the rolling diaphragm 31 of the vacuum valve 15 is put in a
vacuum condition. When the atmosphere is introduced into a
lower portion of the rolling diaphragm 31 at this time, the
plunger 30 is slid upward resisting a force of the push spring
26. In accordance with this upward sliding motion of the
plunger 30, as illustrated in Fig. 2B, the bent portion of the
rolling diaphragm 31 is successively moved upward, and a
portion in which the rolling diaphragm 31 closely coming into
contact with the outer circumferential surface of the plunger
is successively peeled off from the upper portion, and at
the same time the rolling diaphragm 31 closely comes into
25 contact with the inner circumferential surface of the second
housing 22 upward. As described above, the valve operating
48
2~.h :~~D~
chamber 25 above the rolling diaphragm 30 maintains its
airtight condition while its volume is not changed, and is
quickly put in a vacuum condition.
At this time, in accordance with the movement of the
s plunger 30, the bent portion of the rolling diaphragm 31 is
changed. Since lubricant oozes out from the surface of the
rolling diaphragm 31 at all times, even if the opposed bent
portions come into pressure contact with each other, the
abrasion of the bent portion can be suppressed. At the same
1o time, the abrasion of the rolling diaphragm 31 which comes into
contact with the outer circumferential surface o~ the plunger
30 and the inner circumferential surface o~ the second housing
22 can be prevented by the lubricant. Therefore, the rolling
diaphragm 31 can be stably used over a long period of time.
15 When the plunger 30 is moved upward, the valve rod 29
connected with the plunger 30 is slid in an airtight condition
in which the valve rod 29 comes into pressure contact with the
shaft seal 32. Therefore, the valve body 24 connected with a
lower end of the valve rod 29 is moved upward. As a result,
2o the communicating section 28 is put in an open condition.
Since the vacuum discharge pipe 14 is in a vacuum condition,
the suction pipe 13 is also decompressed through the
communicating section 28, so that sewage is sucked into the
suction pipe 13. Sewage sucked into the suction pipe 13 is
zs transported from the communicating section 28 to the vacuum
discharge section 14, and collected into the collection tank.
- 49 -
'~~252~6
Lubricant oozes out at all times from the surface of the
shaft seal 32 which comes into pressure contact with the valve
rod 29 in an airtight condition. Therefore, abrasion of the
shaft seal 32 can be suppressed when the valve rod 29 slides on
the shaft seal 32.
When sewage is discharged into the sewage tank 11 as
described above, pressure in the liquid level detecting pipe 37
is reduced. Due to the foregoing, pressure in the vacuum valve
control device 27 is lowered, and the atmosphere is introduced
to into the vacuum valve control device 27 through the atmosphere '
communicating pipe 43 and hose 44. The atmosphere introduced
into the vacuum valve control device 27 is introduced into the
valve operating chamber 2S through the communicating port 93,
so that the vacuum condition in the valve operating chamber 2S
is canceled. Due to the foregoing, the plunger 30 of the
vacuum valve 1S is moved downward by a force of the push spring
26, and the valve rod 29 slides while the shaft seal 32 comes
into pressure contact with the valve rod 29 under an air tight
condition. In this way, the valve body 24 closes the
2o communicating section 28.
At this time, a portion of the rolling diaphragm 31 which
closely comes into contact with the inner circumferential
surface of the second housing 22, is successively peeled off
from the upper portion, so that the bent portion is moved
zs downward, and the rolling diaphragm 31 successively comes into
21252~~
contact with the outer circumferential surface of the plunger
30 from the lower side to the upper side.
Since lubricant oozes out from the surfaces of the shaft
seal 32 and the rolling diaphragm 31 in this case, abrasion on
the surfaces can be prevented.
Fifth Embodiment
Furthermore, as illustrated in Figs. 2A, 2B, l0A and 10B,
the vacuum valve 15 includes a rolling diaphragm 31 made of
rubber-like resilient substance such as natural rubber and
1o elastomer which is provided between the valve operating chamber
25 and the plunger 30. As illustrated in Fig. 10A, the rolling
diaphragm 31 is formed into a cylindrical shape having a
bottom, and its opening flange portion 31A is interposed
between the connecting portions of both housings 21, 22, and
1s its bottom portion 31B is fixed to the plunger 30. One end
portion of the rolling diaphragm 31 is capable of coming into
pressure contact with the inner surface of the housing 22
composing the valve operating chamber 25, and the other end
portion is capable of coming into pressure contact with the
20 outer surface of the plunger 30.
Due to the construction described above, when the plunger
30 is vertically moved under the balance of 'the spring force of
the spring 26 and the vacuum applied to the valve operating
chamber 25 so that the valve body 24 is opened and closed, one
25 end portion of the rolling diaphragm 31 comes into pressure
contact with the inner surface of the housing 22 composing the
- 51 -
~12~20~
valve operating chamber 25, and under the condition that an
intermediate portion of the rolling diaphragm 31 is folded
back, the other end portion comes into pressure contact with
the outer surface of the plunger 30. Under the aforementioned
condition, the rolling diaphragm 31 is vertically moved
together with the plunger 30. At this time, the rolling
diaphragm 31 is moved as if the intermediate folded portion
between one end and the other end were rolled.
However, in this embodiment, under a free condition of the
1o rolling diaphragm 31 before it is assembled, one end portion
capable of coming into pressure contact with the inner surface
of the housing 22 composing the valve operating chamber 25 is
made to be a large diameter portion 32A, and the other end
portion capable of coming into pressure contact with the outer
surface of the glunger 30 is made to be a small diameter
portion 32B, and the intermediate portion between 32A and 32B
is made to be a tapered portion 32C. Due to the foregoing, as
described later in detail, the bent inside surfaces of the
intermediate folded portion are prevented from corning into
2o contact with each other, so that the abrasion caused when the
surfaces are rubbed can be prevented.
According to the above mentioned fifth embodiment,' in a
free condition before the assembly of the rolling diaphragm 31,
one end portion is made to be a large diameter portion 32A, and
the other end portion is made to be a small diameter portion,
and the intermediate portion is made to be a tapered portion
N 52
21~,~?~~
32C. Accordingly, the bent inside surfaces of the intermediate
folded portion are prevented from coming into contact with each
other when the vacuum valve is used, so that the abrasion
caused when the surfaces are rubbed can be prevented.
Furthermore, even when the valve 15 is repeatedly opened
and closed, abrasion of the rolling diaphragm 31 is not caused,
so that the opening and closing stability of the valve l5,can
be maintained over a long period of time. Moreover, a
replacing period of the rolling diaphragm 31 can be extended,
1o and the labor required for maintenance can be greatly reduced.
In the vacuum valve 15 described above, in the case where
the housing 22 is assembled under the condition that the
rolling diaphragm 31 is attached to the plunger 30, it is
necessary to coat a lubricant on the rolling diaphragm 31 for
making the assembly work easy, because~the sliding resistance
of the rubber-like resilient. body composing the rolling
diaphragm 31 is high. Instead of coating the rolling diaphragm
31 with lubricant, a lubricant such as silicon oil may be
previously kneaded into the rolling diaphragm in the process of
2o forming, and the rubber-like resilient body from which the
lubricant bleeds out may be used for the rolling diaphragm 31.
As described in the above embodiments, in the vacuum valve
control device of the present invention, resilient deformation
of the liquid level detecting diaphragm is quickly canceled.
Therefore, it is possible to quickly return the vacuum valve
from an open condition to a closed condition, and the smooth
operation of the entire system can be guaranteed.
Furthermore, according to the present invention, tha vacuum
valve can be opened at an appropriate opening time in
accordance with vacuum pressure in the vacuum discharge pipe,
and a ratio of air to liquid in the pipe lire can be maintained
in a predetermined range. Therefore, the vacuum type liquid
collecting/transporting apparatus can be stably operated.
Moreover, according to the present invention, in the vacuum
1o valve, the valve opening and closing stability can be
maintained over a long period of time, and the labor necessary
for maintenance can be greatly reduced.
